Apparatus for testing watch balances and hair-springs



( No Model.)

J. LOGAN. APPARATUS FOR TESTING WATCH BALANCES AND HAIR SPRINGS.

No. 406,655. Patented July 9, 1889.

Ill/VE 70/? WITNESSES:

ATTORNEY N. PEIERS Phnlo-Lilhogmphnr. Wuhingwn. u. c.

UNITED STATES PATENT OFFICE.

JOHN LOGAN,'OF WALTHAM, MASSACHUSETTS.

APPARATUS FOR TESTING WATCH BALANCES AND HAIR-SPRINGS.

SPECIFICATION forming part of Letters Patent No. 406,655, dated Ju1y'9,18 89. Application filed MarchlZ, 1889. Serial N0.302 ,996. (No model.)

To all whom it may concern:

Be it known that 1, JOHN LOGAN, of VValtham,in the county of Middlesexand State of Massachusetts, have invented certain new and usefulImprovements in Apparatus for Testing Watch Balances and Hair-Springs,of which the following is a-specification.

This invention relates to the art or method} of testing and gradingbalances and hairsprings of watches and other timekeepers, by gvibratlng said balances and hair-springs by;

Marsh, John Logan, and Duane H. Church, March 29, 1887, No. 360,234, andconsists in@ the improved devices hereinafter described and claimed foradjusting the length of aflat hair-spring after its rate of vibrationhas been ascertained by the apparatus described in the last-namedpatent.

Of the accompanying drawings, forming a part of this specification,Figure 1 represents a side elevation of myimproved devices. Fig. 2represents a vertical section of the same. Fig. 3 represents a sideelevation of apart of the apparatus, showing the adj listing-jaws in adiiferentposition from that shown in Fig. 1. Fig. 4 represents a sectionon line as as, Fig. 2, and a plan view of the parts below said line.

The same letters of reference indicate the same parts in all thefigures.

In the drawings, a represents a chuck, which is attached to or forms apart of one of the arbors of a standard train, such as described andshown in said Patent 360,234, and adapted to receive the staff I) of awatch-balance a, so

that a vibrating rotary motion imparted by the train to the chuck a willbe imparted by the latter to the balance.

(1 represents a standard attached to the top plate c of a casin g inwhich the standard train is located, the chuck a projecting through saidplate.

The standard d has a vertical socket in which is fitted a rod f, havinga narrow horizontal slot or notch f in its lower end adapted to receivethe outer end of a hair-spring g, the inner end of which is connectedwith the balance-staff. To the rod f is pivoted at h a lever i, thelower end of which is formed'with a projection 1', adapted to enter theslot f and cooperate with the bottom of the latter in grasping thehair-spring end inserted between them, the bottom of the slot f and theprojection a" constituting spring grasp'ing or holding jaws. A spring70, attached to the standard cl and bearing against the lever 1', holdstheprojection "L of the latter against the hair-spring and thusmaintains the hold of the jaws on the same. The holding-jaws are locatedabove the balance-staff and sufficiently far from the axial line of thechuck and staff to enable them to correspond to the position of theouter end of the hairspring. The holding-jaws may be vertically adjustedby moving the rod f up or down in its socket in the standard (Z; butthis is not an essential feature, and the jaws may be non-adjustable ifpreferred.

m represents a vertical sleeve fitted to. rotate in a vertical socket inthe standard d, and arranged with its axial 'centerin line with that ofthe chuck a. The lower end of said sleeve is provided with a collar orenlargement m, to one side of which is attached a downwardly-projectingarm n, the lower end of which constitutes a jaw n.

0 represents a bar or lever, pivoted at p to the arm n and having a jaw0 at its lowerend arranged to co-operate with the jaw n in grasping thehair-spring g. A cam-shaped lever q is pivoted at r to the collar m, andbears again st a pin .9, projecting from the upper end of thejaw-lever'b. A movement of the camlever q in the direction indicated bythe arrow in Fig. 1 will -force the jaw 0 toward the jaw 42'. Anoppositemovement of the lever q will release the jaw o and enablea spring 2,bearing on the pin 3, to force the jaw 0 away from the jaw n. The jaws n0', which I designate adj usting-j aws, are located at the same distancefrom the axial center of the chuck a, as are the holding-jaws f e", andthey may be moved by the partial rotation of the sleeve on in itssocket, so as to stand at any desired distance from the holding-jaws.

,In testing a hair-spring, the outer end of 7 areutilized.

the said jaws are moved while opened close to the spring is insertedbetween the holdingjaws f z" and the balance is vibrated a predeterminedlength of time, and its rate of movement, as indicated by a pointer,actuated by the balance-impelling train and moving over a d al, as shownin Patent 360,234, above mentioned, is noted. If the total number ofvibrations is greater or less than the known number of vibrations of astandard balance in the same length of time, the necessity of shorteningor lengthening the hair-spring is apparent, and at this point the adjusting-j aws n 0 If the springis to be shortened,

the spring-holding jaws t" f and are then closed upon the spring. Theholding-jaws being then separated, the sleeve m is turned to move theadjusting-jaws away from the holdin g-j aws, the movement of the adjusting-j aws being in the arc of a circle whose center is the axialcenter of the chuck a. The hair-spring g is thus drawn through theholding-jaws to an extent which is indicated by a finger or pointer r,attached to the sleeve ,m, and a graduated segmental index-plate w,affixed to the standard cl. Said pointer and index-plate enable theoperator to make the exact adjustment of the length of the springrequired to correct the defect indicated by the test above mentioned.After the spring has been thus adjusted the holding-jaws are againclosed upon the spring and the adjusting-jaws are opened, after whichthe surplus end of the spring is broken off by any suitable means closeto the holding-jaws.

In the sleeve m is fitted a plunger '2 which is movable longitudinallyin said sleeve. A rod 2 is fitted to move lengthwise in said plunger,and has a socket or recess in its lower end formed to bear on the upperend of the balance-statf and to steady the same while the plunger 1 isbeing depressed to force the lower end of the balance-staff into thechuck a; or, if desired, it may remain in contact with the balance-staffwhile it-is running. The lower end of the plunger when depressed strikesa shoulder on the balance-staff and forces the latter downwardly intothe chuck. Upon the release of the plunger a spring 2 raises it from thebalance-staff. The plunger has a handle 3, whereby it may be depressed.

It will be seen that by the. conjoint use of the holding-jaws and theadjusting-jaws, the latter being movable in the arc of a circle whosecenter is in line with the center of vibration of the hair-spring, anaccurate adj ustment of I the hair-spring can be very readily andconveniently effected, the convenience of the device being greatlyenhanced by theholding-jaws arranged to hold the outer end of ahair-spring at one side of the center of oscillation of the chuck andadjusting-jaws movable in the arc of a circle whose center is in linewith the said center of oscillation, as set forth.

2. The combination, with an oscillating or reversely-rotating chuck orbalance holder, of holding-jaws arranged to hold the outer end of ahair-spring at one side of the center of oscillation of.the chuck, adjlisting-jaws movable in the arc of a circle whose center is in line withthe said center of oscillation, and a pointer and index-plate, wherebythe. extent of movement of the adjusting-jaws may be determined, as setforth.

3. The combination of the standard (1, having the holding-jaws 17f, andthe sleeve m, journaled in said standard and having the adjusting-jaws n0, as set forth. 7

4:. The standard having the holding-jaws, the sleeve journaled in thestandard, the adjusting-jaws and the pointer on said sleeve,

and the index-plate attached to the standard, all combinedsubstantiallyas set forth.

In testimony whereof I have signed my nam e to this specification, inthe presence of two subscribing Witnesses, this 11th day of February,AD. 1889.

JOHN LOGAN.

Witnesses:

C. F. BROWN, A. D. HARRISON.

